The promotion of energy conservation and global environmental protection is establishing increased standards for more efficient production and utilization of energy in various industrial and commercial sectors. For example, the introduction of Ozone-safe refrigerants presents new challenges. Not only are the new refrigerants considerably more expensive, but the new refrigerants also generally exhibit poor thermal energy transfer characteristics. Additionally, thermal energy transfer devices, such as heat exchangers, condensers, and evaporators, are generally used to effectively utilize heat energy in a variety of applications. For example, condensers and evaporators may be utilized in electronic cooling systems, refrigeration systems, air conditioning systems, solar energy systems, geothermal energy systems and heating and cooling systems in the petrochemical field, the power generation field, the aerospace field, and microgravity environment.
One type of thermal energy transfer device may include an outer tube or conduit enclosing a tube bundle or group of smaller diameter inner conduits. In operation, thermal energy transfer occurs between a fluid disposed within the outer conduit and surrounding the inner conduits and a fluid contained within the inner conduits. In the case of a condenser, the fluid entering the outer conduit may be in a vapor phase which is to be condensed into a liquid phase. The condensation into the liquid phase is generally achieved by providing the fluid within the inner conduits at a temperature below a condensing temperature of the vapor.
Present thermal energy transfer devices, however, suffer several disadvantages. For example, in the case of the condenser described above, as the vapor condenses onto the inner conduits, the liquid condensing on the inner conduits disposed near an upper portion of the condenser falls or drips onto inner conduits disposed in a lower portion of the condenser, thereby decreasing the efficiency of thermal energy transfer of the lower inner conduits. Additionally, liquid condensing on the inner conduits prevents additional vapor from being exposed to the inner conduits, thereby also decreasing the efficiency of thermal energy transfer between the outer fluid and the fluid contained within the inner conduits.
WO 00/71957, the disclosure of which is incorporated herein by reference, presents a solution to the aforementioned problem. However, this reference shows that wires are in the pathway of the liquid that is to be pumped and, therefore, impedes the flow of liquid. Therefore, it is desirable to provide a structure which will achieve the benefits described in the aforementioned document, but provide for an unobstructed movement of liquid on the heat transfer member.